INVESTIGADORES
DORFMAN Damian
congresos y reuniones científicas
Título:
Retinal Neuroprotection Against Ischemia/Reperfusion Damage Induced By Global And Local Hypothermia
Autor/es:
SALIDO EM; DORFMAN D; CHIANELLI MS; ROSENSTEIN RE
Lugar:
Fort Lauderdale
Reunión:
Congreso; Association For Research In Vision And Ophthalmology; 2012
Institución organizadora:
Association For Research In Vision And Ophthalmology
Resumen:
Purpose
Retinal ischemia
could provoke blindness. There is no effective treatment against retinal
ischemic damage. We investigated whether a brief global or local hypothermia
could induce ischemic tolerance in the rat retina.
Methods
Ischemia was
induced in male Wistar rats by increasing intraocular pressure to 140 mm Hg for
50 minutes. One day before ischemia, animals underwent a 20-minute period of
hypothermia by lowering the whole body temperature to 32ºC or by cooling only
one eye to 32ºC for 30 min. Two weeks after ischemia, animals were subjected to
electroretinography (ERG) and histological analysis. Moreover, glutamate uptake
was assessed using 3H-glutamate, and glutamine synthetase activity was assessed
by a spectrophotometric assay.
Results
Retinal ischemia
induced a significant decrease in oscillatory potentials, and scotopic ERG a-
and b-wave amplitude, which was significantly prevented by global or monocular
hypothermia. Retinal ischemia induced a significant decrease in glutamate
uptake and glutamine synthetase activity, whereas monocular hypothermia
prevented the effect of ischemia on glutamate recycling. The intravitreal
injection of supraphysiological concentrations of glutamate mimicked
electroretinographic and histological alterations provoked by ischemia, which
were significantly abrogated by hypothermic preconditioning.
Conclusions
These results
indicate that hypothermia significantly protected retinal function and histology
against ischemia/reperfusion injury. Hypothermic preconditioning could provide
a relatively low-risk approach for treating retinal ischemic pathologies.